The present disclosure relates to a display device including a display portion that displays a message, an image forming apparatus including such a display device and a method of controlling the display device.
Display devices may be attached to various types of electrical and electronic devices. For example, a display device displays a screen for the input of settings of a device or for the operation of the device. Some display devices may display a message showing the state of a device, such as an error or a trouble code corresponding to an error. An example of an image processing device that will be described below and that displays a message according to the state of the device is known.
Specifically, the image processing device includes an operation panel that has a display screen, a display means that displays a main screen and a subscreen on the display screen and a setting means that can set a display form for each type of subscreen. In the image processing device, when the setting means sets whether or not the display of a message is present, the setting means determines, according to the type of the message, whether or not the setting of no display is allowed or prevented; when the message is a message in which the setting of no display is prevented, even if the display of no display is set, the display means displays the message; and the setting means determines, according to the degree of importance of the message, whether the change of the presence and absence of the message is allowed or prevented. For example, the degree of importance is set depending on the type of message, using three levels, large, medium and small.
Not only the state of a device but also an arbitrary (desired) message such as an electronic tag can be displayed on a display device, and thus a display region can be used like a bulletin board, with the result that it is possible to enhance convenience. When an electronic tag is displayed, a user performs an operation for inputting and setting a message (for example, a precaution or an item that is known to each user) and displaying the produced message. Consequently, text, a string of characters or the like that is produced and set is displayed on the display device.
Here, there is a limitation in the size of the display portion (display screen) of the display device. Hence, the number of messages that can be displayed by the display device is limited. Thus, preferably, by reducing the display region of the message or changing the display position of the message, it is possible to change the display form of the message.
However, the degree of importance (the value of information) differs from message to message. A message having a higher degree of importance is made to be more accurately recognized by the user, and it is also necessary to accurately change the display form of the message according to the degree of importance.
Conventionally, for a message that is arbitrarily input by the user (produced by the user), it is impossible to individually set the degree of importance of the message. Hence, conventionally, for the message produced by the user, its display form is not changed in consideration of the degree of importance of the message. Although it is considered that the setting of the degree of importance according to the input and production of the message is allowed, the setting of the degree of importance may be bothersome to the user (in such a case, the degree of importance is often only set normal). An appropriate degree of importance is not necessarily set for the message. An erroneous degree of importance is set, and thus the display device may be difficult to see and use.
The above known technology is a technology on the display of a message that is predetermined (determined as the specification of the device). Hence, it is impossible to apply it to a case where an arbitrary message (for example, an electronic tag) that the user, as necessary, produces, inputs, adds and registers to the device is displayed. Whether or not the message is important for the user is determined not by the type of message but by the details of the message. A preset degree of importance is not necessary appropriate. Hence, it is likely that it is impossible to accurately change the display form of the message according to the degree of importance.